1 #region Copyright notice and license 2 // Protocol Buffers - Google's data interchange format 3 // Copyright 2015 Google Inc. All rights reserved. 4 // https://developers.google.com/protocol-buffers/ 5 // 6 // Redistribution and use in source and binary forms, with or without 7 // modification, are permitted provided that the following conditions are 8 // met: 9 // 10 // * Redistributions of source code must retain the above copyright 11 // notice, this list of conditions and the following disclaimer. 12 // * Redistributions in binary form must reproduce the above 13 // copyright notice, this list of conditions and the following disclaimer 14 // in the documentation and/or other materials provided with the 15 // distribution. 16 // * Neither the name of Google Inc. nor the names of its 17 // contributors may be used to endorse or promote products derived from 18 // this software without specific prior written permission. 19 // 20 // THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS 21 // "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT 22 // LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR 23 // A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT 24 // OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, 25 // SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT 26 // LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, 27 // DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY 28 // THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT 29 // (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE 30 // OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. 31 #endregion 32 33 using System; 34 using System.Collections.Generic; 35 using System.Collections.ObjectModel; 36 using System.Linq; 37 using Google.Protobuf.Collections; 38 using Google.Protobuf.Compatibility; 39 40 namespace Google.Protobuf.Reflection 41 { 42 /// <summary> 43 /// Describes a "oneof" field collection in a message type: a set of 44 /// fields of which at most one can be set in any particular message. 45 /// </summary> 46 public sealed class OneofDescriptor : DescriptorBase 47 { 48 private readonly OneofDescriptorProto proto; 49 private MessageDescriptor containingType; 50 private IList<FieldDescriptor> fields; 51 private readonly OneofAccessor accessor; 52 OneofDescriptor(OneofDescriptorProto proto, FileDescriptor file, MessageDescriptor parent, int index, string clrName)53 internal OneofDescriptor(OneofDescriptorProto proto, FileDescriptor file, MessageDescriptor parent, int index, string clrName) 54 : base(file, file.ComputeFullName(parent, proto.Name), index) 55 { 56 this.proto = proto; 57 containingType = parent; 58 file.DescriptorPool.AddSymbol(this); 59 60 // It's useful to determine whether or not this is a synthetic oneof before cross-linking. That means 61 // diving into the proto directly rather than using FieldDescriptor, but that's okay. 62 var firstFieldInOneof = parent.Proto.Field.FirstOrDefault(fieldProto => fieldProto.HasOneofIndex && fieldProto.OneofIndex == index); 63 IsSynthetic = firstFieldInOneof?.Proto3Optional ?? false; 64 65 accessor = CreateAccessor(clrName); 66 } 67 68 /// <summary> 69 /// The brief name of the descriptor's target. 70 /// </summary> 71 public override string Name { get { return proto.Name; } } 72 73 /// <summary> 74 /// Gets the message type containing this oneof. 75 /// </summary> 76 /// <value> 77 /// The message type containing this oneof. 78 /// </value> 79 public MessageDescriptor ContainingType 80 { 81 get { return containingType; } 82 } 83 84 /// <summary> 85 /// Gets the fields within this oneof, in declaration order. 86 /// </summary> 87 /// <value> 88 /// The fields within this oneof, in declaration order. 89 /// </value> 90 public IList<FieldDescriptor> Fields { get { return fields; } } 91 92 /// <summary> 93 /// Returns <c>true</c> if this oneof is a synthetic oneof containing a proto3 optional field; 94 /// <c>false</c> otherwise. 95 /// </summary> 96 public bool IsSynthetic { get; } 97 98 /// <summary> 99 /// Gets an accessor for reflective access to the values associated with the oneof 100 /// in a particular message. 101 /// </summary> 102 /// <remarks> 103 /// <para> 104 /// In descriptors for generated code, the value returned by this property will always be non-null. 105 /// </para> 106 /// <para> 107 /// In dynamically loaded descriptors, the value returned by this property will current be null; 108 /// if and when dynamic messages are supported, it will return a suitable accessor to work with 109 /// them. 110 /// </para> 111 /// </remarks> 112 /// <value> 113 /// The accessor used for reflective access. 114 /// </value> 115 public OneofAccessor Accessor { get { return accessor; } } 116 117 /// <summary> 118 /// The (possibly empty) set of custom options for this oneof. 119 /// </summary> 120 [Obsolete("CustomOptions are obsolete. Use the GetOptions method.")] 121 public CustomOptions CustomOptions => new CustomOptions(proto.Options?._extensions?.ValuesByNumber); 122 123 /// <summary> 124 /// The <c>OneofOptions</c>, defined in <c>descriptor.proto</c>. 125 /// If the options message is not present (i.e. there are no options), <c>null</c> is returned. 126 /// Custom options can be retrieved as extensions of the returned message. 127 /// NOTE: A defensive copy is created each time this property is retrieved. 128 /// </summary> GetOptions()129 public OneofOptions GetOptions() => proto.Options?.Clone(); 130 131 /// <summary> 132 /// Gets a single value oneof option for this descriptor 133 /// </summary> 134 [Obsolete("GetOption is obsolete. Use the GetOptions() method.")] GetOption(Extension<OneofOptions, T> extension)135 public T GetOption<T>(Extension<OneofOptions, T> extension) 136 { 137 var value = proto.Options.GetExtension(extension); 138 return value is IDeepCloneable<T> ? (value as IDeepCloneable<T>).Clone() : value; 139 } 140 141 /// <summary> 142 /// Gets a repeated value oneof option for this descriptor 143 /// </summary> 144 [Obsolete("GetOption is obsolete. Use the GetOptions() method.")] GetOption(RepeatedExtension<OneofOptions, T> extension)145 public RepeatedField<T> GetOption<T>(RepeatedExtension<OneofOptions, T> extension) 146 { 147 return proto.Options.GetExtension(extension).Clone(); 148 } 149 CrossLink()150 internal void CrossLink() 151 { 152 List<FieldDescriptor> fieldCollection = new List<FieldDescriptor>(); 153 foreach (var field in ContainingType.Fields.InDeclarationOrder()) 154 { 155 if (field.ContainingOneof == this) 156 { 157 fieldCollection.Add(field); 158 } 159 } 160 fields = new ReadOnlyCollection<FieldDescriptor>(fieldCollection); 161 } 162 CreateAccessor(string clrName)163 private OneofAccessor CreateAccessor(string clrName) 164 { 165 // We won't have a CLR name if this is from a dynamically-loaded FileDescriptor. 166 // TODO: Support dynamic messages. 167 if (clrName == null) 168 { 169 return null; 170 } 171 if (IsSynthetic) 172 { 173 return OneofAccessor.ForSyntheticOneof(this); 174 } 175 else 176 { 177 var caseProperty = containingType.ClrType.GetProperty(clrName + "Case"); 178 if (caseProperty == null) 179 { 180 throw new DescriptorValidationException(this, $"Property {clrName}Case not found in {containingType.ClrType}"); 181 } 182 if (!caseProperty.CanRead) 183 { 184 throw new ArgumentException($"Cannot read from property {clrName}Case in {containingType.ClrType}"); 185 } 186 var clearMethod = containingType.ClrType.GetMethod("Clear" + clrName); 187 if (clearMethod == null) 188 { 189 throw new DescriptorValidationException(this, $"Method Clear{clrName} not found in {containingType.ClrType}"); 190 } 191 return OneofAccessor.ForRegularOneof(this, caseProperty, clearMethod); 192 } 193 } 194 } 195 } 196